More than one in every six people in the world is water stressed, meaning that they do not have access to potable water, and an increasing global population has negatively affected the amount and quality of water. With increasing awareness on water conservation, there is continuous interest in toilets and urinals designed to minimize the amount of water being consumed in flushing to mitigate excessive demands on water supplies as well as on wastewater disposal systems.
U.S. Pat. No. 5,711,037 to Reichardt discloses a waterless urinal, which includes an odor trap cartridge unit configured as a coaxial dual chamber bell trap that eliminates the need for conventional P or J type traps required in water-flushing urinals. In the odor trap, a body of oily liquid sealant, floating on a body of trapped residual urine, serves as an odor barrier but allows urine to enter and immediately permeate downwardly through the sealant and proceed to a drain without flushing. The odor trap is molded from two plastic parts that are assembled together to form a cartridge unit that fits readily into a receptacle cavity of urinal bowl configured for wall mounting. The cartridge stays in place by friction and gravity, and can be easily removed with a special tool. However, the odor trap disclosed by Reichardt is difficult to be removed from the urinal for cleaning purposes. Furthermore, the lifespan for the odor cartridge is short so the user may have to replace it frequently, which is not cost effective.
U.S. Pat. No. 7,636,957 to Funari discloses an oil-based odor trap arrangement for a waterless urinal including (a) a bell trap tube received within a cavity situated in a lower portion of the waterless urinal, wherein one end of the tube is adapted to be removably attached to the cavity and (b) a strainer having a body and defining a cap portion and an integrally attached ring portion extending axially away from the cap portion, wherein the strainer is adapted to be received onto an opposite end of the tube whereby the ring portion partially envelopes the tube thus forming a baffle configured to: 1) contain an oil-based substance between the ring portion and a wall of the cavity; 2) accommodate the flow of fluid from the urinal between the ring portion and the tube; and 3) direct the fluid into the tube. However, the oil-based odor trap system is complicated and it may need trained personnel to clean and maintain such a system, which may incur extra costs to the users. Therefore, there remains a need for a new and improved water-preserving urinal that is easy to maintain and clean to overcome the problems stated above.